The stock tires on my 2006 scion xb are 185/60R15. I was planning on buying quieter tires when the stock ones wore out and was looking at the Goodyear Assurance ComforTreds. Unfortunately, they come in 185/65R15. Will my car be able to fit the extra 9.25cm of tire safely? Are there any sides affects I should know about?

I don’t know if your car will accept the difference in tire size or not. In most cases, it is better for the vehicle to go a little smaller than a little bigger, but I wouldn’t want to mess with the aspect ratio when changing tire size. My brother went with a slightly taller tire on his Jeep Grand Cherokee (from stock 245/70R16 to 245/75R16) and rubbed through his splash shields in a matter of months. You may want to check out www.tirerack.com to compare tires available in the stock size for your car. They have consumer reviews, pricing, and other tools available to help you pick out what you want. You may even find a cheaper, quieter tire available in your size.

It will may screw up your odometer because typically they count the rotation of wheels and with a larger wheel it will obviously rotate less times per given distance. Be aware of that. Have someone with an accurate odometer drive a ways with you and measure what distance you both recorded. This will give you an idea of how many miles you are “actually” driving.

My experience with higher profile tires where ABS and fitment was not a problem was always positive. The ride is softer and the speedo will only be slightly off given your change. The handling will only slightly be worsened. Wheel wells in all but high performance sports cars, can handle slightly larger (up to two sizes) tires. I wouldn’t go larger then what you’re attempting. A trial fit at the garage is worthwhile before you buy in ANY size change. You may have trouble getting some garages to sell you tires that aren’t on the recommended list. I would NEVER go smaller in overall diameter… So, if it fits, go for it, I highly recommend this change.

And www.carbibles.com has a calculator that will tell you what the effect will be on the speedo. Since many seem to read a bit faster than actual, yours may even end up more accurate! You may end up actually going the speed that the speedo says!